1. Field of the Invention
This invention relates to a substance comprising a core coated in a waterproof fashion with a film-forming agent which melts when it is heated. More particularly, it relates to an oil or fat coated substance comprising a core and a coating film which does not break or melt at ordinary room temperatures when placed in, for example, food containing water during its manufacturing process which may include cutting, and which melts and thereby allows the core to dissolve in water when it is heated to a high temperature.
2. Discussion of the Background
There are known coated additives for food which comprise cores coated with substances which melt only when they are heated. The cores are, for example, organic acids which are added to boiled fish paste ("kamaboko" in Japanese), sausages, etc. to lower their pH, or 5'-ribonucleotides. The films with which the cores are coated do not melt at ordinary room temperatures and thereby prevent the destruction of the cores by the enzymes which the food contains. The enzymes lose their activity when they are heated.
The temperature to which they are heated depends on the food to which they are added, and has a wide range of from about 50.degree. C. to 90.degree. C. In order to form appropriate films in view of these temperatures, there have been used oils or fats, waxes, solid surface active agents (e.g. monoglyceride and sorbitan ester) or other substances that are waterproof and can prevent the dissolution of the cores into food. When the temperature is from 65.degree. C. to 85.degree. C., carnauba wax and rice wax, which are edible waxes and have a low melting point, have been used. The waxes, however, have a number of drawbacks. They are more expensive than oils and fats. If a large number of wax is used, it separates from the ingredients of food when the molten wax is cooled and the separated wax degrades the appearance of the food or makes it unpleasant to the taste.
Even if grains of additives coated with strong films can be obtained, the films are broken during various stages of a food manufacturing process, for example, when the raw materials are cut or ground or kneaded to manufacture sausages or fish-paste products. As a result, the core substances are dissolved prior to treatment at a high temperature.